Welcome to my Guide for the Kingpin Achievement in Grand Theft Auto Vice City - The Definitive Edition
This is not meant to be a full walkthrough guide, but instead i will give you some important tips on your way to this achievement.
The first thing you should do when starting a new game is the 'Cone Crazy' money making method. There are several guides on how this works, so please look it up and this will give you a headstart. You will need to do this until you gained over 100 million dollars. By doing this, you can achieve the Godfather Criminal Rating, which you will not be able to do by just playing the game to 100% (I ended up somewhere around 25,000 criminal rating after i completed the game and you need a criminal rating of 100,000 for this rank).
Afterwards i suggest you to complete the Pizza Delivery (150HP), 25 cab fares (just to have the achievement done) and the Paramedic Level 12 (giving you infinite sprint which is very annoying to not have).
There are multiple missable achievements that you should be aware of before you start doing main and side missions. Iron-y (kill the guy on the golf course with a golf club), complete G-Spotlight without falling of the roof, kill Ricardo Diaz with a M-16 (which you automatically get during the mission) and Chopper'd Up (Kill all NPCs during the Demolition Man mission where you drop bombs with the RC Helicopter (Averys 2nd Mission).
Everything else can be achieved at any point in the game, but i advise you to do side missions and collectibles as soon as you are comfortably able to (e.g. collect all 100 hidden packages once you reached the main land).
After you completed Cop Land and you have access to the police outfit and you collected all 100 hidden packages, go to the military base, they will not shoot you if you wear the police uniform. You can now easily get the Hunter and do the Lv12 Vigilante mission with that brown thunder.
My last tip, there is currently a glitch that allows you to skip doing the Rampages and 100 taxi fares (you still need to do 25) by abusing the Checkpoint Charlie mission at the boatyard. If you buy the boatyard, do the Checkpoint Charlie mission (use the left boat, it is much faster than the right one). After finishing the mission, drive back to the boatyard, save your game and load the gamefile that you just saved. Then instantly go and redo the Checkpoint Charlie mission (you can use the left boat again). Repeat the process and you will get 0.67% per run.
Thanks for reading, i hope i can save you some valuable hours of your life (02.02.2023)